Marine sanctuary officials are still working to cut loose a young humpback whale entangled in several hundred yards of heavy plastic rope in waters off Maui.

The rope runs through the animal's mouth, around its head and behind its blowhole. It is twisted in a knot.

It could kill the yearling humpback if it stays in too long, said Ed Lyman, marine mammal response manager with the Hawaiian Islands Humpback Whale National Marine Sanctuary. Right now, however, the animal appears healthy.

“;If we can cut one side of the knot, then we can pull hard on the other side and try to pull it out of the whale's mouth,”; Lyman said.

A whale-watching cruise spotted the entangled animal Tuesday in waters off Maui. The next day, about a hundred yards of the yellow, polypropylene line came free, but several hundred yards are still attached.

Lyman's crew used a knife attached to a pole reaching out about 10 to 15 feet to try to cut the rope Wednesday but could not reach it. Officials did not go in the water yesterday because of windy weather and because the whale was farther offshore.

The crew planned to return today with a pole specially fashioned by Lyman that is more than 24 feet long. They are able to follow the whale's whereabouts using a tracking device that they attached to the rope on Tuesday.

Complicating the task is the fact that two adult whales are traveling with the juvenile. The adult whales — believed to be the juvenile's mother and the mother's escort — have been sandwiching the young whale by almost constantly swimming on either side of it.

Another difficulty is that the whale's mouth is normally submerged unless it is coming up for air.

“;They come up from the nose, take that breath, clear that blowhole, and basically there's only a second or two there,”; Lyman said.

It is not clear where the rope came from. Lyman's guess is that it got caught in the whale's mouth when the animal was feeding in Alaska or other northern waters. Judging by the wounds on the whale's body, it appears the rope got stuck in its mouth a month or two ago.

The whale could probably eat if it needed to, but the animals tend to fast for long periods this time of year.

About 10,000 humpback whales come to Hawaii every winter to breed and calve after spending the summer feeding in northern waters. The whales are an endangered species, though their numbers have grown in recent years.